Introduction Irritable bowel syndrome (IBS) and gastro-esophageal reflux disease (GERD) are common disorders in the general population, and there is thought to be a degree of overlap between the two. However, the strength of this association has not been examined systematically. We performed a systematic review and meta-analysis to estimate the prevalence of GERD in individuals with IBS.

Methods MEDLINE, EMBASE, and EMBASE Classic were searched through October 2011 for cross-sectional surveys reporting the prevalence of IBS. A recursive search of the bibliographies of identified articles was also conducted. There were no language restrictions. Eligible studies were population-based, recruited ≥50 adult (≥15 years) subjects, and were required to define IBS via the Manning or Rome criteria, or according to a questionnaire. Eligibility assessment and data extraction were conducted independently in a double-blind fashion by two investigators, with any discrepancies resolved by consensus. Data were extracted and pooled, with a random effects model, to estimate prevalence of IBS in the population under study. The prevalence of GERD in individuals with and without IBS was compared using an OR, with a 95% CI.

Results The search yielded 20 146 results, of which 390 studies appeared relevant and were retrieved for further assessment. There were 80 separate population-based studies that reported the prevalence of IBS according to the various criteria defined above. Of these, 13 studies, containing 49 939 participants, also reported the proportion of people who met criteria for GERD within the same population. The pooled prevalence of IBS in these 13 studies was 11.6% (95% CI 7.1% to 17.1%). The odds of GERD in individuals with IBS, compared with those without, was 4.17 (95% CI 2.85 to 6.09). Odds of GERD in individuals with IBS varied according to the criteria used to define IBS (see Abstract PWE-059 table 1).

Conclusion The prevalence of GERD in individuals with IBS was fourfold that in those without. The degree of overlap varied according to the criteria used to define IBS, but remained significant in all cases. The strength of this association suggests common pathogenetic mechanisms.

Competing interests None declared.